Preface: This question applies only to writing, which lacks the benefits of nonverbal communication which would resolve this problem.
Example: Your lawyer remembers your remembrance that she cannot do something (eg: She can advise only on real estate law, and not trust law in which she is inexperienced.). However, her excessive caution causes her to keep reminding you redundantly. How do you most tactfully inform her that she need not remind you? My attempts below all sound impolite.
Please do not repeat it.
Problem: This sounds too authoritative, even with 'please'.
Please, (there is) no need to repeat it.
Problem: This sounds as though her reminders have dispirited and fatigued you.
Please do not worry about repeating it.
Problem: My own experiences attest and prove this ineffective; the other parties rebut me by insisting that they are not 'worried', and then repeat it anyways to my annoyance.